Lettuce harvesting apparatus and method therefor

ABSTRACT

A mobile harvesting apparatus and method, which permits the automated harvesting of produce, preferably lettuce. The apparatus consists in its most basic form of a vehicle having a bandsaw positioned at a front portion thereof, the blade of which is positioned to slice the lettuce head at the desired location. The apparatus further includes a conveyor, that transports the harvested produce from the cutting site and onto the apparatus. Preferably, the apparatus additionally features a washing conveyor, washing station, inspection station, and elevator conveyor, to assist in the further processing of harvested produce.

RELATED APPLICATION

This non-provisional application claims priority from provisionalapplication No. 60/368,990, filed on Apr. 2, 2002.

FIELD OF INVENTION

This invention relates generally to apparatuses and methods forharvesting produce and, more specifically, to a mobile lettuce harvesteradapted to permit the automated harvesting of lettuce heads.

BACKGROUND OF THE INVENTION

Generally, the harvesting of produce, including in particular lettuce,involves the manual removal of produce from the field. Typically, afarmworker will walk through a field with a cutting tool such as aknife, and manually detach the exposed lettuce head from its root. Thelettuce head will then be delivered for further processing, perhaps to aconveyor belt on a self-propelled harvester travelling through the fieldalongside the worker.

There are several drawbacks with the prior art methods, however. Theyare labor-intensive and, because of the use of a sharp cutting implementby the workers, potentially dangerous. A need therefore existed toreduce the labor-intensity of the produce harvesting process, and alsoto make that process safer. Preferably, account should also be taken ofother steps necessary in the harvesting process beyond the removal ofthe produce from the ground, including inspection, washing, andelevation of the produce to a container. The present invention satisfiesthis need and provides other, related advantages.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a mobile harvesterpermitting automated harvesting of produce, including specificallylettuce.

It is a further object of the present invention to provide a mobileharvester permitting automated harvesting of produce, and further havinga conveyor belt, a washing station, and an elevator belt.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with one embodiment of the present invention, aself-propelled harvester is disclosed. The harvester comprises, a mobileharvesting apparatus traveling on a plurality of wheels and powered byan engine, a bandsaw having an exposed cutting blade positioned at afront portion of the apparatus wherein the level of the cutting blademay be adjusted by a leveling feature, and a conveyor for conveying theharvested produce.

In additional embodiments, the harvester may further comprise a washingstation, shaking means for shaking excess water from the harvestedproduce, an inspection area, and additional conveyors.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an embodiment of the lettuce harvestingapparatus of the present invention.

FIG. 2 is a front view of the lettuce harvesting apparatus of FIG. 1.

FIG. 3 is a side view of another embodiment of the lettuce harvestingapparatus of the present invention.

FIG. 4 is a front view of the lettuce harvesting apparatus of thepresent invention, illustrating in greater detail the bandsaw portion ofthe apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to FIG. 1, an embodiment of the lettuce harvestingapparatus 10 (“apparatus 10”) of the present invention is shown. Theapparatus 10 is intended to be used for the harvesting of produce. It ispreferred to use the apparatus 10 to harvest lettuce, and in particularromaine lettuce.

The major components of the apparatus 10 include a bandsaw 12, a feedconveyor 14, a lift conveyor 16, a washing conveyor 18, a washingstation 20, a transfer conveyor 22, and an elevator conveyor 24. Theapparatus 10 is powered by an engine 26, rides on wheels 28, and may bedriven by a person 29 sitting in driving compartment 30.

The bandsaw 12 is positioned at the front of the apparatus 10 as shownin FIGS. 1-4. The exposed cutting blade 15 of the bandsaw 12 ispositioned at the base of the feed conveyor 14. The height of thebandsaw 12 and thus of the exposed cutting blade 15 is preferablyadjustable, and the desired height setting will depend on the specificproduce to be cut. Generally, with romaine, the height of the exposedcutting blade 15 will be set between 0.25″ and 1.5″ from the ground. Thelevel of the bandsaw 12, and thus of the exposed cutting blade 15, ispreferably also adjustable, as herein described.

Preferably, the bandsaw 12 further comprises a housing 17, whichconceals the cutting blade 15 after it passes across the area where itwill be cutting the produce, and continues to loop upward and around.(The path of the cutting blade 15 is illustrated in FIG. 4.) The purposeof the housing 17 is to increase safety for persons who might be workingwith the apparatus 10. The bandsaw 12 is preferably poweredhydraulically, though of course other powering means may be employed.

The feed conveyor 14 is coupled to the lift conveyor 16 with couplingarms 32, which coupling arms 32 are to travel in an upward and downwarddirection about the point at which they couple to the lift conveyor 16.The feed conveyor 14 preferably rides on five parallel rollers 34 (onlyone is shown), with the rollers 34 being positioned about axle 35 andwith axle 35 being coupled at each end thereof to a substantiallyL-shaped member 37. Each substantially L-shaped member 37 rotates aboutpoint B, and is coupled at its second end (the first end being coupledto axle 35) to a hydraulic cylinder 13 (only one of which is shown). (Itshould be understood that fewer than five, or more than five, rollers 34could be provided, and further that they could be positioned in anon-parallel configuration.) It is further preferred to positionscrapers (not shown) above each roller 34, oriented so as to remove dirtor debris that adheres to the surface of the rollers 34 as the apparatus10 travels through a field to be harvested.

The feed conveyor 14 is coupled to the coupling arms 32 with firstvertical supports 36 and second vertical supports 38. The first verticalsupports 36 include a spring and shock assembly 40 thereon, so as topermit upward and downward movement of the front portion of the feedconveyor 14, as indicated by the bi-directional arrow, in response tovariations in the terrain over which the apparatus 10 travels.

The second vertical supports 38 are rotatably coupled below the surfaceof the feed conveyor 14 about point A, which is a centrally-locateduniversal joint. As the front of the feed conveyor moves upward ordownward—either by operation of the herein-described height adjustmentmechanism or in response to terrain variations—the feed conveyor ispermitted to rotate about points A and B. This permits the feed conveyor14 to remain relatively stable during operation.

The entire feed conveyor 14 preferably maintains a generally upwardangle, as indicated in FIG. 1. The belt 42 of the feed conveyor 14travels in an upward direction, so as to move harvested produce from thefront of the feed conveyor 14 upward toward the lift conveyor 16.

Turning now to the lift conveyor 16, as shown in FIGS. 1 and 2, it ispreferably oriented in an upward direction, when viewed moving backwardalong the apparatus 10 from the feed conveyor 14. The feed conveyor 14is preferably oriented at about a 45 degree angle. The belt 44 of thefeed conveyor 14 preferably has a plurality of outwardly projectingsteps 46. The purpose of the steps 46 is to prevent the produce fromfalling backward as it is moved upward along the lift conveyor 16.

The lift conveyor 16 is preferably slidably retained on a frame 11 onthe main body of the apparatus 10, and may be raised or lowered alongthe frame 11 by activation of a hydraulic cylinder (not shown). Raisingor lowering of the lift conveyor 16 along the frame 11 will also causethe feed conveyor 14 to be raised or lowered as well, by virtue of theherein-described coupling of the feed conveyor 14 to the lift conveyor16. In this manner, it is possible to raise or lower the exposed cuttingblade 15, so as to position it at the desired height for optimumcutting.

For purposes of describing the levelling feature of the apparatus 10,attention is now drawn to hydraulic cylinders 13 (only one of which isshown), which couple between axle 35 and the substantially L-shapedmember 37. When it is desired to adjust the horizontal level of theexposed cutting blade 15, typically because of the terrain of the areato be harvested, such levelling can be accomplished by the individualextension or contraction of the hydraulic cylinders 13, which will havethe effect of rotating the substantially L-shaped members 37 about pointB and thereby raising or lowering the side of the feed conveyor 14proximate the activated hydraulic cylinder 13.

When the produce reaches the topmost point of the lift conveyor 16, itwill pass to the washing conveyor 18. As the produce moves along thewashing conveyor 18, it will pass through a washing station 20.Referring now to FIG. 1, the washing station 20 in one embodimentconsists of a plurality of spray nozzles 21 located above the washingconveyor 18, so as to spray water downward onto the produce passingbelow. Referring now to FIG. 3, the washing station 20 in anotherembodiment consists of a plurality of spray nozzles 21 located above thewashing conveyor 18 and a plurality of spray nozzles 21 located belowthe washing conveyor 18. In this embodiment, the produce is sprayed fromabove and below. (In the embodiment shown in FIG. 3, the belt 48 willneed to be configured so as to permit the passage of water therethrough,such as by forming holes in the belt 48. The water sprayed through thespray nozzles 21 is preferably stored in water tank 50.

Referring now to FIG. 1, in one embodiment, a portion of the washingconveyor 18 may be left exposed from the top thereof, so as to permitone or preferably two persons 29 to be positioned there. From thatposition, the persons 29 may inspect the produce as it passes along thewashing conveyor 18, for purposes of quality control. Alternatively, orin combination with the inspection step, one or more persons 29 couldremove harvested produce (or a portion of harvested produce—e.g., theheart or the leaves) from the washing conveyor 18 for packaging. (Itshould be noted that it would also be possible to position the exposedportion after the washing station 20.)

Referring now to FIG. 3, in one embodiment, a plurality of shaker bars52 are positioned below the belt 48, and oriented so that movement ofthe shaker bars 52 causes shaking of the belt 48. This shaking movementwill cause some of the water remaining on the produce after its passagethrough washing station 20 to be removed. Referring now to FIGS. 1 and3, from the end of the washing conveyor 18, the produce will pass to atransfer conveyor 22, which is preferably oriented at a right angle tothe washing conveyor 18. The transfer conveyor 22 will move the produceto the elevator conveyor 24. Like the lift conveyor 16, the elevatorconveyor 24 preferably has a plurality of outwardly projecting steps 46thereon so as to prevent the produce from falling backward as it travelsupward. At the terminus of the elevator conveyor 24, at exit point B,the produce is dumped into a receptacle (not shown), which may be atruck bed or other suitable vessel.

While the invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that the foregoing and other changes in formand details may be made therein without departing from the spirit andscope of the invention. For example, it may be possible to operate thefeed conveyor 14 with the bandsaw 12 as a stand-alone unit, so as toachieve the advantage of automated cutting of the produce—and thenperforming the washing and loading steps separately. Moreover, the feedconveyor 14 and lift conveyor 16 could be combined into a singleconveyor. Still further, it would be possible to eliminate the transferconveyor 22, and instead to configure the elevator conveyor 24 incombination with the steps 46 so that produce could pass directly fromthe washing conveyor 18 to the elevator conveyor 24 without fallingbackward. Yet further, it would be possible to eliminate both thetransfer conveyor 22 and elevator conveyor 24, with dumping of theproduce taking place at the terminus of the washing conveyor 18.

1. A produce harvester comprising, in combination: a mobile harvestingapparatus travelling on a plurality of wheels and powered by an engine;a bandsaw positioned at a front portion of a feed conveyor located onsaid mobile harvesting apparatus; wherein said bandsaw has an exposedcutting blade located at an appropriate height for harvesting produce;and a lift conveyor positioned on said mobile harvesting apparatus so asto receive harvested produce exiting said feed conveyor; wherein saidlift conveyor is slidably retained on said mobile harvesting apparatus;and wherein said lift conveyor and said feed conveyor are rotatablycoupled to each other, so that sliding of said lift conveyor adjusts avertical position of said bandsaw.
 2. A method of harvesting producecomprising the steps of: utilizing the apparatus of claim 1, adjusting avertical position of said bandsaw by sliding said lift conveyor on saidmobile harvesting apparatus.